PR binutils/15140

	* ar.c (open_inarch): Fail on attempts to convert a normal archive
	to a thin archive or vice versa.
	* elfcomm.c (make_qualified_name): Handle corrupted thin
	archives.
	* readelf.c (process_archive): Likewise.
	* doc/binutils.texi: Clarify documentation describing thin
	archives.

	* archive.c (_bfd_get_elt_at_filepos): Prevent an infinite loop
	accessing a corrupt nested archive.

1 files changed, 16 insertions, 10 deletions

diff --git a/binutils/doc/binutils.texi b/binutils/doc/binutils.texi
index d733fdb..0bb1d92 100644
--- a/binutils/doc/binutils.texi
+++ b/binutils/doc/binutils.texi
@@ -10,10 +10,7 @@
 
 @copying
 @c man begin COPYRIGHT
-Copyright @copyright{} 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
-2010, 2011, 2012, 2013
-Free Software Foundation, Inc.
+Copyright @copyright{} 1991-2013 Free Software Foundation, Inc.
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3
@@ -221,12 +218,21 @@ table.  If an archive lacks the table, another form of @command{ar} called
 @cindex thin archives
 @sc{gnu} @command{ar} can optionally create a @emph{thin} archive,
 which contains a symbol index and references to the original copies
-of the member files of the archives.  Such an archive is useful
-for building libraries for use within a local build, where the
-relocatable objects are expected to remain available, and copying the
-contents of each object would only waste time and space.  Thin archives
-are also @emph{flattened}, so that adding one or more archives to a
-thin archive will add the elements of the nested archive individually.
+of the member files of the archive.  This is useful for building
+libraries for use within a local build tree, where the relocatable
+objects are expected to remain available, and copying the contents of
+each object would only waste time and space.
+
+An archive can either be @emph{thin} or it can be normal.  It cannot
+be both at the same time.  Once an archive is created its format
+cannot be changed without first deleting it and then creating a new
+archive in its place.
+
+Thin archives are also @emph{flattened}, so that adding one thin
+archive to another thin archive does not nest it, as would happen with
+a normal archive.  Instead the elements of the first archive are added
+individually to the second archive.
+
 The paths to the elements of the archive are stored relative to the
 archive itself.